Conventionally, a working robot is widely used in a working field such as a production factory. It is general that a working field in which the working robot is placed is provided with a safe guard fence that is provided sufficiently away from a movable range of the working robot around the working robot to prevent contact between the working robot and an operator and to reduce an impact on the operator.
However, a working robot that performs a joint work together with a person without using a safe guard fence attracts attention recently. For example, Japanese Laid-open Patent Publication No. 2010-120139 discloses, for example, a working robot that provides an efficient working environment by assisting a work operation in which an operator is weak.